1. Field of the Invention
The present invention relates to an apparatus for reproducing a color video signal and, more particularly, to an apparatus for reproducing a color video signal recorded in a recording medium by a TCI (time compressed integration) signal format.
2. Description of the Related Art
A TCI system has received a great deal of attention as a recording system suitable for improving image quality in a VTR (video tape recorder) and a video disk system. According to a TCI system, a luminance signal (Y signal) and chrominance signals (C signals) are multiplexed within a 1H period (one horizontal scanning period) along the time base, as shown in FIG. 1. The TCI signal is essentially free from interference between the luminance and chrominance signals, unlike an NTSC signal. In the TCI system, in order to transmit the chrominance signals through one channel instead of two originally channels. In practice, as shown in FIG. 1, the chrominance signals had been classified into two types of chrominance signal (color difference signals), i.e., a wide-band chrominance signal (C.sub.W signal) and a narrow-band chrominance signal (C.sub.N signal). These two chrominance signals are selected by a predetermined rule (e.g., alternately selected every horizontal scanning period) every horizontal scanning period and inserted in a TCI signal in accordance with a so-called color line sequential scheme.
In order to accurately extract the chrominance signal from the TCI signal of the color line sequential scheme, the line sequential order of the chrominance signals in the TCI signal must be appropriately maintained (e.g., the C.sub.W and C.sub.N signals alternately appear every horizontal scanning period). However, in a helical scan type VTR for recording a color video signal by a TCI signal format using a color line sequential scheme, the line sequential order of the chrominance signals is not often maintained in a special reproduction mode such as a still reproduction mode and a slow motion reproduction mode in which a tape speed is different from that during recording. This problem will be described with reference to FIGS. 2, 3, and 4 in which a segment recording scheme suitable for recording a wide-band video signal such as a high-quality television signal is exemplified.
In the segment recording scheme, a one-field video signal is divided into a plurality of segments (e.g., three segments), as shown in FIG. 2. These segments are divided into different tracks, and information is recorded in these tracks, as shown in FIG. 3. A scan trace of a magnetic head upon reproduction of the recorded signal at a tape travel speed twice the recording speed is indicated by broken lines in FIG. 3. In this case, as shown in FIG. 4, signals of segments .circle.1 and .circle.2 , signals of segments .circle.3 and .circle.4 , and signals of segments .circle.5 and .circle.6 are obtained as reproduced signals in the first, second, and third scanning cycles in FIG. 3, respectively. The contents of the chrominance signals in the signals reproduced by the respective scanning cycles are shown in FIG. 5. As shown in FIG. 2, all segment chrominance signals alternately appear as C.sub.W and C.sub.N signals. However, the order of the C.sub.W and C.sub.N signals in an odd segment is opposite to that in an even segment. These reproduced signals are reordered in an order of horizontal scanning line numbers, identical chrominance signals continue for a 3H period, as shown in FIG. 6. Therefore, the correct line sequential order cannot be maintained.
When special reproduction described above is performed in a helical scan VTR, a noise bar appears on the screen. In order to eliminate noise, in a general VTR of a non-segment recording scheme for recording a one-field video signal in one track, as disclosed in Japanese Patent Disclosure (Kokai) No. 60-117885, when information is reproduced upon traveling of the tape at a speed in an even multiple of the recording speed, interfield (between the odd and even fields) interpolation of a reproduced signal is performed. However, this technique cannot be directly applied to the segment recording scheme.